A boy living in Wakayama Prefecture accidentally comes into possession of an Adélie penguin egg and successfully hatches it. However, wanting to return the penguin to its natural habitat, he embarks on a journey to Antarctica. Along the way, in Central and South America, he faces hardships, such as being robbed by impoverished local children. The story is framed as the recollections of Ryota Ichikawa, now an adult, reflecting on his boyhood.